Municipal potable water systems are necessary to transport water from a water treatment facility to an urban development for consumers to use for drinking, use to cook, and other water use in a domestic environment. The water is processed and treated to meet the drinking water standards. The treatment plant processes the water to remove impurities and adds chemicals to bring the water into compliance with the Environmental Protection Agency (EPA) regulations.
The purified water is pumped into several storage tanks and storage basins around the city for release into the distribution system piping network on demand for consumer use.https://www.usfa.fema.gov/downloads/pdf/publications/water_supply_systems_volume_i.
pdf 2. Surface water runoff estimation, diversion, and routing are needed in designing an area to make sure the area will not flood and the water diverted into the proper drains and channels. Since there are no exact methods for hydrologic analysis, different methods that may commonly be used may produce different results for a specific site and particular situations. The random nature of rainfall, snowmelt and other sources of water can complicate the process. The most important step prior to hydraulic design is estimating the discharge or volume of runoff that the drainage facility will be required to control.Urbanization is the most dominant factor affecting the hydrology of an area and nearly always causes increases in surface water runoff. A good drainage design can anticipate the future development and land use changes and the estimation of design discharge in the hydraulic analysis.http://www.
Flow in natural and constructed channels can be analyzed and designed similarly. A natural stream channel addresses the whole system. Fluvial geomorphology (FGM) is the study of a stream’s interactions with the local climate, geology, topography, vegetation and land use an how the river or stream carves its channel within the landscape. It is much easier to work with the streams natural form and function than to try and redirect it and work against it.http://www.
streamteamok.net/OST%20documents/Nat%20Stream%20Channel%20Design%20Guide%20Penn%202003.pdfConstructed channels such as roadside channels, median channels and street gutters are also used in helping to direct the flow of water to an outlet to prevent flooding or erosion of the ground.http://epg.modot.
org/index.php?title=750.1_Open_Channels 4. Flow in pressurized pipe systems, including pumps and pumping is used to provide sufficient pressure to move the fluid through the system at a desired flow rate. Pressure, friction and flow are the three important characteristics of a pump system. The driving force that is responsible for the movement of the fluid is pressure.
Friction is the force that slows down the fluid particles. Flow rate is the amount of volume that is displaced per unit time. The unit of measure in North America’s pump industry is gallons per minute (gpm). Pressure is expressed in pounds per square inch (psi) means the pressure measurement is relative to the local atmospheric pressure. So 5 psi is 5 psi above the local atmospheric pressure. Pressure provides the driving force to overcome friction and elevation difference.http://www.pumpfundamentals.
com/tutorial1.htm 5. Water wells – there are drilled wells which are constructed by either cable tool (percussion) or rotary-drilling machines. Drilled wells that penetrate unconsolidated material required installation of casing and screen to prevent inflow of sediment and collapse. They can be drilled more than 1,000 feet deep. The space around the casing must be sealed with grouting material of either neat cement or bentonite clay to prevent contamination by water draining from the surface downward around the outside of the casing.
Driven wells are constructed by driving a small-diameter pipe into shallow water-bearing sand or gravel. Usually a screened well point is attached to the bottom of the casing before driving. These wells are relatively simple and economical to construct, but they can tap only shallow water and are easily contaminated from nearby surface sources because they are not sealed with grouting material. Hand-driven wells usually are only around 30 feet deep; machine-driven wells can be 50 feet deep or more.Dug wells. Historically, dug wells were excavated by hand shovel to below the water table until incoming water exceeded the digger’s bailing rate. The well was lined with stones, bricks, tile, or other material to prevent collapse, and was covered with a cap of wood, stone, or concrete tile. Because of the type of construction, bored wells can go deeper beneath the water table than can hand-dug wells.
Dug and bored wells have a large diameter and expose a large area to the aquifer. These wells are able to obtain water from less-permeable materials such as very fine sand, silt, or clay. Disadvantages of this type of well are that they are shallow and lack continuous casing and grouting, making them subject to contamination from nearby surface sources, and they go dry during periods of drought if the water table drops below the well bottom.
http://wellowner.org/basics/types-of-wells/ 6. Storm water systems, including culverts.
Urbanization has many benefits but there are also downsides that severely affect the environment. For instance, vegetation and soil need to be removed, drainage networks need to be built, and land surface needs to be reshaped—all of which contribute to peak discharge, frequency, and volume of floods in nearby streams. Some of the biggest aspects of urbanization contribute to flooding in many different ways. City planners make it a point to include flood protection in their priorities. A variety of technologies are available toward this end, including bioinfiltration, enhanced tree pits, pocket wetlands, green roofs, and subsurface detention, retention, and infiltration practices.Four types of subsurface stormwater systems are:Storage Vaults or Tanks Storage vaults and tanks designed to mitigate flooding are typically constructed from pre-cast concrete structures, culverts, concrete rings, pipes, cast-in-place concrete, and even vendor-provided products.
They can be built with or without a bottom slab, depending on whether the intention is to let stormwater runoff infiltrate the ground or overflow.Gravel Beds – are excavated subterranean areas filled with uniformly-graded gravel. They are meant to temporarily detain water and promote infiltration. The void spaces within the gravel are where excess water can be stored.Perforated pipes – come in a variety of sizes.
They help ease soggy yards, flooded fields, and wet basements. They can be made of different materials including PVC plastic, cement, clay, and iron. Perforated pipes typically combine the methods of gravel and pipe storage to detain water and promote infiltration.Storm Chambers – are underground structures that can be used either for detention or retention of stormwater. Many consider storm chambers to be the best storm water systems available because, apart from being less expensive, quicker, and easier to install than other underground systems, they are extremely reliable when it comes to meeting and exceeding the standards of water quality BMP. http://stormchambers.
com/4-types-of-subsurface-storm-water-systems-that-you-should-get-to-know/ A culvert conveys surface water through a roadway embankment or away from the highway right-of-way (ROW) or into a channel along the ROW. In addition to the hydraulic function, the culvert must also support construction and highway traffic and earth loads; therefore, culvert design involves both hydraulic and structural design. The hydraulic and structural designs must be such that minimal risks to traffic, property damage, and failure from floods prove the results of good engineering practice and economics.
Culverts are considered minor structures, but they are of great importance to adequate drainage and the integrity of the facility. This chapter describes the hydraulic aspects of culvert design, construction and operation of culverts, and makes references to structural aspects only as they are related to the hydraulic design.Culverts, as distinguished from bridges, are usually covered with embankment and are composed of structural material around the entire perimeter, although some are supported on spread footings with the streambed or concrete riprap channel serving as the bottom of the culvert. For economy and hydraulic efficiency, engineers should design culverts to operate with the inlet submerged during flood flows, if conditions permit. Bridges, on the other hand, are not covered with embankment or designed to take advantage of submergence to increase hydraulic capacity, even though some are designed to be inundated under flood conditions. Any culvert with a clear opening of more than 20-feet, measured along the center of the roadway between inside of end walls, is considered a bridge by FHWA, and is designated a bridge class culvert. (See Chapter 9, Section 1).
This chapter addresses structures designed hydraulically as culverts, regardless of length.At many locations, either a bridge or a culvert fulfills both the structural and hydraulic requirements for the stream crossing. The appropriate structure should be chosen based on the following criteria:Construction and maintenance costsrisk of failurerisk of property damagetraffic safetyenvironmental and aesthetic considerationsConstruction expedience.http://onlinemanuals.
txdot.gov/txdotmanuals/hyd/culverts.htm 7. Sanitary Sewer Systems including gravity and pressurized systems pressure sewer system (PSS) which offers a far more reliable and controllable transfer of sewage from the household to the treatment plant than conventional alternatives. This sewage handling solution is ideal for domestic communities, and it is growing rapidly in popularity thanks to the many advantages it offers over a conventional gravity-fed system. PSS makes use of small, low-powered, grinder pumps in each property, which are each connected to a central discharge network. Each of these units will have a high-density polyethylene storage tank with a typical capacity of around 900-litres (approximately 197 gallons), a progressing cavity (PC) pump, plus a cutter which breaks down the solids in the sewage to create a transferable slurry. An automatic electronic controller will also be included to regulate the flow, monitor fluid levels, and protect the pump.
The grinder ensures that the sewage is reduced to a manageable consistency before the pumps at each property transfer it away via a central ‘community’ network, usually to a pump station and on to a treatment plant. The network serving the community is normally constructed from small diameter pipes which can be installed in narrow, shallow trenches, or via the use of directional drilling techniques. This increases the speed and safety of the installation process compared to a conventional alternative, as well as dramatically reducing overall construction costs. It also provides greater control over the network’s design and layout so that genuinely bespoke solutions can easily be created. Benefits As no gravity is required to operate the system, a PSS offers controlled transfer of sewage in a far more efficient footprint than conventional sewage systems, and as such it provides unlimited possibilities.
A modern PSS offers impressive performance, great reliability and the potential to be expanded as the demand for sewage handling increases. Ease of installation also makes the PSS particularly popular for use in difficult terrain. It now becomes possible to install a network in rocky, hilly, coastal or other difficult areas, such as those with high water tables where conventional gravity-fed sewers would be too costly.
A PSS offers the freedom to build and develop wherever the need exists, even in areas that were once off-limits, or those with only a low population but who must nevertheless be provided with a reliable and efficient solution. An effective PSS will also address environmental concerns that surround many of today’s new developments. Their low impact construction characteristics minimize disruption to the local environment during installation, while their comparatively small footprint means less vegetation removal. The better systems are also completely sealed, which eliminates the opportunity for any sewage or contaminated liquid to leak into the surrounding area. Odor issues are therefore dramatically reduced by a PSS, and most systems are also perfectly compatible with effluent re-use schemes. A PSS offers a host of other benefits too, not least the fact that it needs absolutely no input from the property owners it serves. This effectively makes a good PSS ‘invisible’ to the end user, but there are also many benefits for the network operator.
So what features should we be looking for when we’re evaluating a possible PSS for a project? Perhaps the best starting point is to consider the two key points of a good PSS, which are its ability to grind and its ability to pump the sewage effectively. With these in mind it makes good sense to look at a PSS offered by a manufacturer who has a proven track record in both these areas. A system that can deliver a high degree of flexibility is a must.
One that offers a wide range of tank sizes, plus single and dual pumping options, will ensure that a bespoke network can be created to suit the size, scale and individual requirements of the development being served. This flexibility can also help improve cash flow for developers by allowing the networks to be scaled up as a development increases in size. This allows them to use a staged investment process by reducing the up-front capital costs involved.It’s also well worth investigating whether a PSS will allow for the possibility of a hybrid PSS/gravity system to be created.
If the PSS ‘plays well with others’, it can usually be made to integrate seamlessly with existing networks and installed in conjunction with other brands, without inhibiting overall performance. This provides greater control over various features of the wider network design, such as the location of pump stations. https://www.wateronline.
com/doc/the-advantages-of-pressure-sewer-systems-vs-gravity-fed-systems-0001 Gravity Sewer System, uses gravity (no moving parts) to convey wastewater from your home to a neighborhood wastewater pump station, which pumps wastewater to our regional wastewater treatment facility where wastewater is treated and recycled to meet landscape irrigation needs. Gravity sewers are preferred where grades are favorable, but lift stations often move sewage to sewage treatment plants. 8. Water and Wastewater treatment plants – One of the most common forms of pollution control in the US is wastewater treatment. The country has a vast system of collection sewers, pumping stations, and treatment plants. Sewers collect the wastewater from homes, businesses, and many industries, and deliver it to plants for treatment. Most treatment plants were built to clean wastewater for discharge into streams or other receiving waters, or for reuse.
The basic function of wastewater treatment is to speed up the natural processes by which water is purified. There are two basic stages in the treatment of wastes, primary and secondary, which are outlined here. In the primary stage, solids are allowed to settle and removed from wastewater. The secondary stage uses biological processes to further purify wastewater. Sometimes, these stages are combined into one operation.Primary Treatment – As sewage enters a plant for treatment, it flows through a screen, which removes large floating objects such as rags and sticks that might clog pipes or damage equipment. After sewage has been screened, it passes into a grit chamber, where cinders, sand, and small stones settle to the bottom. A grit chamber is particularly important in communities with combined sewer systems where sand or gravel may wash into sewers along with storm water.
After screening is completed and grit has been removed, sewage still contains organic andinorganic matter along with other suspended solids. These solids are minute particles that can beremoved from sewage in a sedimentation tank.When the speed of the flow through one of thesetanks is reduced, the suspended solids will gradually sink to the bottom, where they form a mass ofsolids called raw primary biosolids formerlysludge). Biosolids are usually removed from tanksby pumping, after which it may be further treated for use as a fertilizer, or disposed of in a land fill orincinerated. Over the years, primary treatment alone has been unable to meet many communities’ demandsfor higher water quality.
To meet them, cities and industries normally treat to a secondary treatmentlevel, and in some cases, also use advanced treatment to remove nutrients and other contaminants.Secondary Treatment The secondary stage of treatment removes about 85 percent of the organic matter in sewage by making use of the bacteria in it. The principal secondary treatment techniques used in secondarytreatment are the trickling filter and the activated sludge process. After effluent leaves the sedimentation tank in the primary stage it flows or is pumped to a facility using one or the other of these processes.
A trickling filter is simply a bed of stones from three to six feet deep through which sewage passes. The trend today is towards the use of the activated sludge process instead of trickling filters. The activated sludge process speeds up the work ofthe bacteria by bringing air and sludge heavily laden with bacteria into close contact with sewage. After the sewage leaves the settling tank in the primary stage, it is pumped into an aeration tank, where it is mixed with air and sludge loaded with bacteria and allowed to remain for several hours. During this time, the bacteria break down the organic matter into harmless by-products. The sludge, now activated with additional billions of bacteria and other tiny organisms, can be used again by returning it to the aeration tank for mixing with air and new sewage. From the aeration tank, the partially treated sewage flows to another sedimentation tank for removal of excess bacteria. To complete secondary treatment, effluent from the sedimentation tank is usually disinfected with chlorine before being discharged into receiving waters.
Chlorine is fed into the water to kill pathogenic bacteria, and to reduce odor. Done properly, chlorination will kill more than 99 percent of the harmful bacteria in an effluent. Some municipalities now manufacture chlorine solution on site to avoid transporting and storing large amounts of chlorine, sometimes in a gaseous form. Many states now require the removal of excess chlorine before discharge to surface waters by a process called dechlorination. Alternatives to chlorine disinfection, such as ultraviolet light or ozone, are also being used in situations where chlorine in treated sewage effluents may beharmful to fish and other aquatic life. https://www3.epa.
gov/npdes/pubs/bastre.pdf 9. Water-energy nexus – Research performed by the Energy Commission has found that water and energy resources are inextricably connected, and this is known as the Water-Energy Nexus. Transportation and treatment of water, treatment and disposal of wastewater, and the energy used to heat and consume water account for nearly 20 percent of the total electricity and 30 percent of non-power plant related natural gas consumed in California.
Demand for water resources is expected to rise primarily due to population growth and also as a result of external factors such as climate change and more strict regulatory rules protecting water quality. Water-related electricity use is 48 terawatt-hours (TWh) per year and accounts for nearly 20% of California’s total electricity consumption.